System and method for creating and using temporary data storage in an Xforms application

ABSTRACT

A system and method for enabling the use of temporary data in an XForms application without requiring the data to be included in the application&#39;s instance data. An XForms author includes an extension element in an XForms markup document. The extension element describes element and attributes of desired temporary instance data. The temporary data can be read and written as normal XForms instance data. The temporary data may or may not be serialized, depending on whether exposure to an external data consumer is or is not desired.

RELATED APPLICATION

This application claims priority to U.S. Provisional Application Ser. No. 60/511,220, filed on Oct. 15, 2003, which is hereby incorporated by reference.

BACKGROUND

This invention relates generally to the field of computer programming. More particularly, a system and method are provided for facilitating the use of temporary data storage within an XForms application.

There are many languages and interfaces designed to help one define, generate and/or present a web form or other document accessed and manipulated via a web browser. Some of the markup language options include HTML (HyperText Markup Language), XHTML (eXtensible HyperText Markup Language), WML (Wireless Markup Language) and HDML (Handheld Device Markup Language). However, these markup languages compel an author to merge the functional and presentation aspects of a form.

XForms, developed by the World Wide Web Consortium (W3C), is a specification for a forms markup language that uses a layered approach to allow the presentation of a form to be separated from its content. More particularly, XForms treats a web form as a composition of three layers: data, logic and presentation. The data layer identifies data fields in the form. The logic layer identifies constraints and dependencies on or between data fields. The presentation layer defines what the form looks like when it is output on a printer or computer screen. XForms documents can be viewed using a web browser or other application interface on virtually any type of computing device, including personal digital assistants and mobile telephones.

Because the XForms architecture is intended to provide a medium for a structured interchange of data, the collection or definition of an XForms document is important. Data used in a document are typically referred to as the document's “instance data,” and may be represented using an XML (eXtensible Markup Language) schema. Data are fed to an XForms processor, which applies the document's logic and presentation interface.

XForms instance data may be generated by a third party, and may reside internal or external to a particular XForms document or page. At runtime, an XForms document consumes specified instance data, and can modify the data and submit the modified data to an external consumer.

However, the XForms 1.0 specification allows XForms documents to manipulate the content, but not the structure, of instance data. For example, an XForms document can clone or modify XML elements and attributes included in the document's instance data. An XForms document author wishing to use temporary data storage (e.g., for application state management only within the context of the XForms application), would have to ensure that the storage was provided for in the document's instance data. But this may be difficult.

For example, if the instance data is provided by a third party, that third party may know nothing about the specific user interface and/or data management requirements of the document. Or, the third party may be unwilling to provide temporary data storage requested by one customer, if the data are provided to multiple customers. Yet further, an XML schema may constrain the data in a manner that would disallow the one customer's attributes.

In addition, temporary data storage that is included in the document's instance data and therefore serialized, would be exposed to any external consumer of the instance data. This may be undesirable in some cases.

SUMMARY

A system and method are provided for facilitating the use of temporary data storage in an XForms document or application, wherein the temporary data need not be defined in the document's instance data.

In one embodiment of the invention, an XForms extension element is introduced to allow an XForms document author to declare new temporary instance data elements and attributes inside an XForms document. In this embodiment, an extension element is embedded within an XForms document, and describes element names and attributes of the desired temporary instance data. The temporary data can be read and written as normal XForms instance data.

Thus, an XForms instance data provider, which may be separate from the development team of an XForms application that will consume the data, need not provide temporary instance variables for the application.

Further, an application may selectively serialize temporary data, depending on whether exposure to external data consumers is desired. In particular, annotation nodes may be configured to specify whether they are serialized, by using Boolean XPath expressions for example.

DESCRIPTION OF THE FIGURES

FIG. 1 depicts an XForms application environment, in accordance with an embodiment of the present invention.

FIG. 2 depicts an illustrative runtime DOM (Document Object Modeling) tree formed from a source instance document and an annotation instruction, according to one embodiment of the invention.

FIG. 3 depicts the annotation of a multi-node nodeset, according to one embodiment of the invention.

FIG. 4 depicts the annotation and submission of an XForms document, with conditional serialization, according to one embodiment of the invention.

FIG. 5 demonstrates the use of an annotation extension to add elements and attributes, with conditional serialization, according to one embodiment of the invention.

FIGS. 6A and 6B demonstrates an embodiment of the invention implemented to facilitate relevance toggling, according to one embodiment of the invention.

FIG. 7 presents a sample instance data document for use with the embodiment of the invention depicted in FIGS. 6A and 6B.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of particular applications of the invention and their requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

In one embodiment of the invention, an XForms extension element is introduced to allow an XForms author to declare new temporary instance data elements and attributes inside an XForms document. Thus, unlike the existing XForms repeat construct, annotation instance data nodes can be inserted at runtime, without existing prototype nodesets.

An implementation of this embodiment of the invention enhances the XForms repeat structure by cloning annotation instance elements under a repeat set. The present XForms specification offers no means of creating arbitrary instance data nodes that can be cloned in such a fashion.

The extension element introduced in this embodiment provides a declarative structure for inserting element and attribute nodes into XForms instance data at runtime. For example, a collection of XML elements in a specified namespace may be enclosed within the standard XForms <extension> element.

Thus, in this embodiment, temporary data storage may be inserted into an XForms application at the model layer, without requiring the provider of instance data to include the storage in the application instance's data. This may be particularly useful if the instance data are provided by a source other than the developer of the application.

And, because the temporary data storage is not provided as part of the instance data, it need not be serialized. For example, classes of annotation instance data nodes can be selectively serialized. Unwanted exposure of the temporary data to external consumers can therefore be avoided. Standard XForms, in contrast, only allows filtering of serialized data through XPath expressions.

FIG. 1 is a block diagram of an XForms environment, according to one embodiment of the invention. In FIG. 1, XForms model 102 is a definition of an XML form, as specified by the XForms specification. The XForms model defines constraints and other run-time aspects of XForms. For example, XForms model 102 describes the structure of instance data 106. Various presentation modules may be employed as user interfaces for the XForms model, such as XForms user interface 104 a, XHTML 104 b, WML 104 c, etc. XForms user interface 104 a provides a set of visual controls for replacing form controls such as those deployed with XHTML.

In an embodiment of the invention, an extension element is exposed within an XForms markup (e.g., XForms model 102 of FIG. 1), and describes element names and attributes of the desired temporary instance data, which can be read and written as normal XForms instance data.

In one implementation of this embodiment, an <annotate> element appears under an XForms <extension> element, and wraps a set of <addAttribute> and <addElement> elements. An <addAttribute> element or <addElement> attributes adds a new attribute or a new element, respectively, to the instance data nodeset specified in a corresponding XPath expression in the “nodeset” attribute of the <annotate> element.

The following XML schema is one example of how these <extension> elements may be employed in an XForms markup:

EXAMPLE 1

<xs:element name=“annotate” xml:namespace= “http://www.oracle.com/2003/XClient/TemporaryVariable”> <xs:complexType> <xs:sequence> <xs:element name=“addAttribute”> <xs:complexType> <xs:attribute name=“name” type=“xs:string”/> <xs:attribute name=“serialize” type=“xs:string”/> <xs:complexType> </xs:element> <xs:element name=“addElement”> <xs:complexType> <xs:attribute name=“name” type=“xs:string”/> <xs:attribute name=“serialize” type=“xs:string”/> </xs:complexType> </xs:element> </xs:sequence> <xs:attribute name=“nodeset”/> </xs:complexType> </xs:element>

The extension element allows an XForms application developer to describe element names and attributes of the specified temporary instance data. In Example 1, the temporary instance data attributes and elements added with the annotation framework (i.e., addAttribute and addElement) may appear and behave as any other instance data attributes or elements. However, the attributes and elements may reside in the specified namespace (i.e., http://www.oracle.com/2003/XClient/TemporaryVariable) rather than the default namespace for instance data.

Temporary data may or may not be serialized when the XForms document does a submission, depending on whether it is to be exposed to an external XForms application data consumer. Default behavior may be to prevent serialization of temporary data elements and attributes.

One skilled in the art will appreciate that an embodiment of the invention may be deployed as an extension to the XForms specification, available at http://www.w3.org, and may therefore be useful with an XForms language processor or an XForms-enabled application.

An implementation of the invention is particularly suitable for wireless devices that are compatible with XForms. In this implementation, the invention is embodied in the wireless client as a set of additional element handlers within the XForms processor. This implementation requires no modification to any server-side components or existing XForms document instance data.

As one skilled in the art will appreciate, an XForms processor sees an XForms document and the corresponding instance data as a set of DOM (Document Object Model) trees. In particular, the XForms document and the instance document are treated as separate DOMs, even if the instance document is embedded in the source XForms document.

FIG. 2 depicts an illustrative runtime DOM tree formed from a source instance document (comprising instance data) and an annotation instruction (comprising a novel extension element), according to one embodiment of the invention.

In FIG. 2, source instance document 202 comprises two datum entries, each with a single attribute. Annotation instruction 204 specifies that a temporary element (tempElem) is to be added to a nodeset comprising one node—the first datum node. Runtime DOM tree 206 depicts the result of annotation: two datum elements under the data node, with tempElem under the first datum element. Source instance document 202 may be provided by an external or third-party, or may be included in the XForms model document.

FIG. 3 depicts the annotation of a multi-node nodeset, according to one embodiment of the invention. Source instance document 302 mirrors document 202 of FIG. 2, while annotation instruction 304 includes an addAttribute tag to add a temporary attribute (tempAttr) to each node of the nodeset. Runtime DOM tree 306 demonstrates the result of annotation, with the temporary attribute and temporary element (tempElem) added to each datum node. Illustratively, if a datum node were cloned (e.g., using ‘<xforms:insert ref=“data/datum”/>’), the cloned node would also include tempAttr and tempElem.

FIG. 4 depicts the annotation and submission of an XForms document, with conditional serialization, according to one embodiment of the invention. Source instance document 402 includes two empty datum nodes, while annotation instruction 404 mirrors annotation instruction 304 of FIG. 3, but also includes serialize statements for tempElem and tempAttr. Runtime DOM tree 406 shows the resulting DOM tree, and serialized document 408 show the result of submission.

In this embodiment tempElem will be serialized, because of the statement ‘serialize=“true”’. The statement ‘serialize=“position( )=2”’ stipulates that only the second tempAttr attribute will be serialized.

FIG. 5 also demonstrates the use of the annotation extension to add elements and attributes, with conditional serialization, according to an embodiment of the invention. In FIG. 5, source instance document 502 includes two datum nodes, one of which includes a subnode. Annotation instruction 504 adds temporary elements and attributes, and specifies conditional serialization. Runtime DOM tree 506 demonstrates the DOM tree formed for the instance data as a result of annotation, while serialized document 508 shows the result of submission.

In this embodiment, the tempElem elements are conditionally serialized, depending on whether the specified XPath expression in the “serialize” attribute evaluates to true( ). The expression can be as simple or as complicated as the developer chooses. The tempAttr attributes are serialized, but the tempChildAttr attribute is not.

Another example of the use of temporary data storage is now described in conjunction with FIGS. 6-7. In the embodiment of the invention depicted in FIG. 6, temporary variables are employed to enable relevance toggling. Relevance toggling requires an attribute within the model of an XForms application, to allow one to specify whether certain user interface controls (within the presentation layer of the XForms application) should or should not be displayed, based on certain values or conditions within the instance data.

In this example, the XForms application comprises accounting or financial functionality (e.g., an expense report), and relevance toggling is used to toggle between summary and detailed views of receipts. The instance data, depicted in FIG. 7, are provided by an external source. Because that source is merely concerned with providing the expense data, it does not attempt to provide for various views of the data. By applying temporary variables through annotation instructions and enabling relevance toggling, we can allow one to view a summary of all expenses, or the details of a single expense.

FIGS. 6A-B present the entire XForms document 602, embedded within an XHTML document, which includes a reference to the location (expenseData.xml) of Instance Data Document 702 (FIG. 7) and annotation instructions, and defines a user interface button for toggling between the summary and detailed views of expenses.

The head portion of document 602 adds a temporary attribute “display,” which will be used to indicate whether a detailed view (i.e., Long Description) or summary view (i.e., Short Description) of an expense should be presented. The <xforms:trigger> sections in the body of the document define a trigger for toggling between the views. The DOMActivate event reflects a user's activation of a user interface control.

Although embodiments of the invention have been described as adding specific tags to an XForms document model (e.g., <addElement>, <addAttribute>), the tags used to delineate temporary data may be different in other embodiments, and may be inserted in various locations of the document model.

The program environment in which a present embodiment of the invention is executed illustratively incorporates a general-purpose computer or a special purpose device such as a hand-held computer. Details of such devices (e.g., processor, memory, data storage, display) may be omitted for the sake of clarity.

It should also be understood that the techniques of the present invention may be implemented using a variety of technologies. For example, the methods described herein may be implemented in software executing on a computer system, or implemented in hardware utilizing either a combination of microprocessors or other specially designed application specific integrated circuits, programmable logic devices, or various combinations thereof. In particular, the methods described herein may be implemented by a series of computer-executable instructions residing on a suitable computer-readable medium. Suitable computer-readable media may include volatile (e.g., RAM) and/or non-volatile (e.g., ROM, disk) memory, carrier waves and transmission media (e.g., copper wire, coaxial cable, fiber optic media). Exemplary carrier waves may take the form of electrical, electromagnetic or optical signals conveying digital data streams along a local network, a publicly accessible network such as the Internet or some other communication link.

The foregoing descriptions of embodiments of the invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the invention to the forms disclosed. Accordingly, the above disclosure is not intended to limit the invention; the scope of the invention is defined by the appended claims. 

1. A computer-implemented method of enabling temporary data storage in an XForms application, the method comprising: selecting a set of instance data to be consumed during execution of an XForms application; in an XForms model document for the application, defining temporary data for use during the execution of the application by: inserting an <addElement> tag configured to identify a temporary data element to be added to the instance data for execution of the application; and inserting an <addAttribute> tag configured to identify a temporary attribute to be added to the instance data for execution of the application; and processing the model document with an XForms processor, during which a node is added to a runtime document object modeling tree for each temporary data element, wherein the modeling tree is configured to model the instance data.
 2. The method of claim 1, further comprising: inserting a serialization instruction into the model document, for a first temporary data element, to indicate whether the first temporary data element should be serialized during execution of the XForms application.
 3. The method of claim 2, wherein the serialization instruction is conditional, so that serialization of the first temporary data element depends on a state of the first temporary data element or the instance data during execution of the XForms application.
 4. The method of claim 1, further comprising: inserting a serialization instruction into the model document, for a first element of the instance data, to indicate whether the first element of the instance data should be serialized during execution of the XForms application.
 5. The method of claim 4, wherein the serialization instruction is conditional, so that serialization of the first element of the instance data depends on a state of the first element of the instance data or a temporary data element during execution of the XForms application.
 6. A computer readable medium storing instructions that, when executed by a computer, cause the computer to perform a method of enabling temporary data storage in an XForms application, the method comprising: selecting a set of instance data to be consumed during execution of an XForms application; in an XForms model document for the application, defining temporary data for use during the execution of the application by: inserting an <addElement> tag configured to identify a temporary data element to be added to the instance data for execution of the application; and inserting an <addAttribute> tag configured to identify a temporary attribute to be added to the instance data for execution of the application; and processing the model document with an XForms processor, during which a node is added to a runtime document object modeling tree for each temporary data element, wherein the modeling tree is configured to model the instance data.
 7. A computer-implemented method of enabling temporary data storage in an XForms application, the method comprising: identifying a set of instance data for an XForms application; generating an XForms model document for the application; in the model document, defining one or more temporary data elements not included in the set of instance data; and processing the model document and the instance data through an XForms processor.
 8. The method of claim 7, further comprising: defining one or more attributes for each of the temporary data elements.
 9. The method of claim 7, wherein said processing comprises: generating a document object model tree modeling the instance data; and augmenting the tree with nodes corresponding to the temporary data elements.
 10. The method of claim 7, further comprising: in the model document, specifying serialization instructions for the temporary data elements, to indicate whether the temporary data elements are to be serialized.
 11. The method of claim 10, wherein said specifying comprises: for a first temporary data element, inserting a conditional serialization instruction that will cause the first temporary data element to be serialized depending on a state of the instance data and the first temporary data element.
 12. A computer readable medium storing instructions that, when executed by a computer, cause the computer to perform a method of enabling temporary data storage in an XForms application, the method comprising: identifying a set of instance data for an XForms application; generating an XForms model document for the application; in the model document, defining one or more temporary data elements not included in the set of instance data; and processing the model document and the instance data through an XForms processor.
 13. An application framework for using temporary data storage within an XForms application, the framework comprising: an XForms processor; a user interface module configured to present output of the application; an instance data module received from a third party and configured to contain instance data to be consumed during execution of the application; and a data model configured to execute a set of markup language, the markup language including one or more temporary data elements; wherein said one or more temporary data elements are not included in the instance data module.
 14. The application framework of claim 13, wherein said data model comprises a portion of an XForms model document for the XForms application.
 15. The application framework of claim 13, wherein said data model further comprises one or more temporary attributes for each temporary data element.
 16. The application framework of claim 13, wherein said data model further comprises one or more temporary attributes for the instance data.
 17. The application framework of claim 13, wherein the temporary data elements are linked to the instance data when the instance data module and the data model are processed by the XForms processor.
 18. The application framework of claim 13, wherein the data model further comprises serialization instructions to indicate whether a temporary data element should be serialized during execution of the XForms application.
 19. The application framework of claim 13, wherein the data model further comprises serialization instructions to indicate whether an element of the instance data should be serialized during execution of the XForms application.
 20. The application framework of claim 13, wherein said data model is distinct from said instance data module.
 21. The application framework of claim 20, wherein said instance data module is provided by a source other than a source of the data model.
 22. The application framework of claim 13, wherein said data model and said instance data module are part of a single XForms model document. 